Chip capacitor performance introduction

Chip capacitors are among the most widely used components in modern electronics, known for their compact size, high capacitance, and ease of integration. They play a critical role in mobile communication devices, computer boards, and household appliance remote controls. As electronic devices continue to evolve toward miniaturization, high performance, and cost efficiency, chip capacitors have also advanced rapidly. Their design has become more diverse, with smaller sizes, improved performance, and more sophisticated materials. These advancements have enabled them to transition from consumer-grade applications into more specialized industrial and commercial fields.

In addition, chip capacitors are undergoing a trend of diversification to meet different application requirements:

• For portable communication devices, they are being developed to operate at lower voltages, with higher capacities, and ultra-thin, ultra-small designs.
• To support high-performance systems like military communication equipment, high-voltage, high-current, and high-Q chip capacitors are becoming increasingly important.
• For highly integrated circuits, multi-functional composite chip capacitors are gaining attention as a research focus.

1. Chip Laminated Ceramic Dielectric Capacitors

The most commonly used type of chip capacitor is the laminated ceramic dielectric capacitor. Also known as multilayer ceramic capacitors (MLCC), these capacitors are made by layering ceramic dielectric films with printed internal electrodes, then sintering them at high temperatures to form a solid ceramic body. Electrodes are added on both ends, creating a monolithic structure. This design allows for a large number of parallel plate capacitors to be stacked, significantly increasing the overall capacitance.

The formula for calculating the capacitance of an MLCC is: C = NKA/t, where N is the number of electrode layers, K is the dielectric constant, A is the area of the electrode, and t is the thickness of the dielectric material. To achieve higher capacitance while maintaining a small size, manufacturers often increase the number of layers or use high-K materials. However, this can affect stability and reliability, so careful material selection is crucial.

Common ceramic dielectrics include MgTiO3, CaTiO3, SrTiO3, and TiO2, often combined with rare earth oxides to enhance performance. Class I ceramics (like COG/NPO) offer excellent stability, while Class II ceramics (like X7R, Y5V, Z5U) provide higher capacitance but with greater temperature sensitivity.

2. Key Performance Indicators of Chip Capacitors

Several key parameters define the performance of chip capacitors:

• Capacitance and Tolerance: The deviation between actual and nominal capacitance values. Common tolerances include ±0.5% (D), ±1% (F), ±2% (G), ±5% (J), ±10% (K), and ±20% (M).
• Rated Voltage: The maximum DC voltage the capacitor can handle without failure. Higher voltage ratings generally mean larger physical dimensions.
• Temperature Coefficient: Measures how capacitance changes with temperature. Lower coefficients indicate better stability.
• Insulation Resistance: Reflects leakage current. Higher resistance means less leakage.
• Loss Factor: Represents energy loss due to dielectric and metallic losses, typically expressed as a tangent of the loss angle.
• Frequency Characteristics: Capacitance and loss vary with frequency, especially in high-frequency applications.

3. Applications in EMI Suppression

Chip capacitors are widely used in electromagnetic interference (EMI) suppression, particularly in filtering, decoupling, and bypassing applications. In power supply circuits, they help remove unwanted AC signals, smoothing out ripple voltages. In signal paths, they prevent interference between circuit sections and reduce noise. When used with other components like chip beads or inductors, their EMI suppression capabilities are further enhanced.

4. Chip Capacitor Configurations

Two-terminal chip capacitors are the most common type, offering versatility across a wide range of applications. Murata’s GRM series, for example, includes capacitors suitable for wave soldering and reflow processes, available in various sizes and voltage ratings. Three-terminal capacitors are designed to minimize lead inductance, improving high-frequency performance by reducing self-resonance effects.

As technology continues to advance, chip capacitors will remain essential in the development of next-generation electronics, driven by demands for smaller, faster, and more reliable components.